1. Field of the Invention
The invention relates to an image forming apparatus or the like such as a copying apparatus or the like and, more particularly, to an image forming apparatus or the like to which a post-processing apparatus and a trimming apparatus are attached and which can execute a binding process.
2. Related Background Art
Hitherto, there has been known an image forming system in which, to an image forming apparatus for reading an image of an original and forming the read image onto a transfer material (paper), a post-processing apparatus for executing a binding process such as stapling process, folding process, sorting process, and the like to the paper on which the image has been formed and a trimming apparatus for executing a cutting process to the sheets of paper subjected to the binding process by the post-processing apparatus are attached.
By attaching such post-processing apparatus and trimming apparatus, not only the operations for the stapling, folding, sorting, and the like of the paper can be lightened but also the bound paper of higher quality can be obtained by cutting overflow portions of the folded and stacked paper obtained after completion of the binding process.
The above conventional image forming system, however, has a problem such that if the sheets of paper subjected to the binding process by the post-processing apparatus are further subjected to the cutting process by using the trimming apparatus, a distance between a paper edge of the paper in a paper bundle obtained after completion of the cutting process and an image forming area, that is, a width of blank portion differs every paper and is not constant, so that binding quality deteriorates.